The invention relates to a tank closing device for a filler neck of a container, in particular of an operating liquid or fuel tank of a transportable work tool such as a disk grinder, a motorised chain saw, an independent cutting tool or similar.
A closing device for a radiator is known from U.S. Pat. No. 3,027,043. In this device, a closing member is biassed against the filler neck by a spring and a sealing member is arranged between the closing member and the filler neck. The spring biassing the closing member is braced against a closing cap which can be secured on the filler neck by means of a bayonet fitting. In this design, the closing cap has two radial shoulders, which are used for handling purposes when opening or closing the cap. These shoulders can be used to apply increased torque.
In many cases, however, the mounting design of containers and their filler necks is so restricted in terms of space that radial shoulders can not always be provided on closing caps.
Furthermore, a design which provides only two oppositely lying locking members for the bayonet fastening causes the filler cap to be tilted transversely, which means that the force applied to the filler cap is very uneven. This can cause the closing member to lift at a point on the circumference of the filler neck so that a momentary look is caused in this manner.
The object of the present invention, therefore, is to provide a tank closing device for a filler neck of a container of the aforementioned kind, which is easy to operate even if the design is restricted in terms of space, as well as functionally safe and provides a reliable seal under the most varied of operating conditions.